Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Triangulum Pinwheel: 07-28 (88), 07-29 (88), 07-27 (87), 07-26 (84), 07-25 (82) — by astronomy; check the weather when the night is within four days.

2042-06-30astronomy score per night — click a bar for that night2042-07-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-06-30 Mon	27	—	unknown	03:00–03:45 (good, 0.75 h)	79.2° 08:20	4.52	94%	140.8°
2042-07-01 Tue	25	—	unknown	02:55–03:45 (good, 0.83 h)	79.2° 08:15	4.54	98%	129.3°
2042-07-02 Wed	25	—	unknown	02:55–03:45 (good, 0.83 h)	79.2° 08:10	4.56	100%	117.2°
2042-07-03 Thu	22	—	unknown	03:00–03:45 (good, 0.75 h)	79.2° 08:10	4.59	99%	104.5°
2042-07-04 Fri	19	—	unknown	03:05–03:45 (good, 0.67 h)	79.2° 08:05	4.61	97%	91.5°
2042-07-05 Sat	18	—	unknown	02:05–03:50 (marginal, 1.75 h)	79.2° 08:00	4.64	92%	78.3°
2042-07-06 Sun	16	—	unknown	02:05–03:50 (marginal, 1.75 h)	79.2° 07:55	4.67	84%	65.1°
2042-07-07 Mon	16	—	unknown	02:00–03:50 (marginal, 1.83 h)	79.2° 07:50	4.7	75%	51.9°
2042-07-08 Tue	17	—	unknown	01:55–03:50 (marginal, 1.92 h)	79.2° 07:50	4.73	65%	39.2°
2042-07-09 Wed	20	—	unknown	01:50–03:50 (marginal, 2.0 h)	79.2° 07:45	4.77	54%	27.7°
2042-07-10 Thu	27	—	unknown	02:35–03:55 (good, 1.33 h)	79.2° 07:40	4.8	42%	19.6°
2042-07-11 Fri	33	—	unknown	02:25–03:55 (good, 1.5 h)	79.2° 07:35	4.84	31%	19.7°
2042-07-12 Sat	41	—	unknown	02:05–03:55 (good, 1.83 h)	79.2° 07:30	4.88	21%	27.8°
2042-07-13 Sun	48	—	unknown	02:00–03:55 (good, 1.92 h)	79.2° 07:30	4.92	13%	39.1°
2042-07-14 Mon	53	—	unknown	01:55–04:00 (good, 2.08 h)	79.2° 07:25	4.96	6%	51.4°
2042-07-15 Tue	57	—	unknown	01:55–04:00 (good, 2.08 h)	79.2° 07:20	5.0	2%	64.0°
2042-07-16 Wed	59	—	unknown	01:50–04:00 (good, 2.17 h)	79.2° 07:15	5.05	0%	76.6°
2042-07-17 Thu	62	—	unknown	01:45–04:05 (good, 2.33 h)	79.2° 07:15	5.09	1%	89.0°
2042-07-18 Fri	63	—	unknown	01:40–04:05 (good, 2.42 h)	79.2° 07:10	5.14	3%	101.1°
2042-07-19 Sat	66	—	unknown	01:40–04:05 (good, 2.42 h)	79.2° 07:05	5.18	8%	113.0°
2042-07-20 Sun	68	—	unknown	01:35–04:05 (good, 2.5 h)	79.2° 07:00	5.23	14%	124.4°
2042-07-21 Mon	72	—	unknown	01:30–04:10 (good, 2.67 h)	79.2° 06:55	5.28	21%	135.5°
2042-07-22 Tue	74	—	unknown	01:25–04:10 (good, 2.75 h)	79.2° 06:55	5.33	29%	145.8°
2042-07-23 Wed	76	—	unknown	01:20–04:10 (good, 2.83 h)	79.2° 06:50	5.38	38%	154.9°
2042-07-24 Thu	80	—	unknown	01:20–04:15 (good, 2.92 h)	79.2° 06:45	5.43	47%	160.9°
2042-07-25 Fri	82	—	unknown	01:15–04:15 (good, 3.0 h)	79.2° 06:40	5.48	57%	160.7°
2042-07-26 Sat	84	—	unknown	01:10–04:15 (good, 3.08 h)	79.2° 06:35	5.53	66%	154.4°
2042-07-27 Sun	87	—	unknown	01:10–04:20 (good, 3.17 h)	79.2° 06:35	5.58	75%	144.8°
2042-07-28 Mon	88	—	unknown	01:10–04:20 (good, 3.17 h)	79.2° 06:30	5.64	84%	133.7°
2042-07-29 Tue	88	—	unknown	01:05–04:20 (good, 3.25 h)	79.2° 06:25	5.69	90%	121.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-06-30&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.